Introduction to dementia, Cost-Benefit Analysis, and the new interventions

Using the medical definition of dementia in terms of brain pathology is not useful at this time. Medical interventions that can alter brain pathology do not yet exist. Sticking to this medical definition would mean that, currently, nothing can be done to intervene to reduce dementia. By contrast, if we define dementia in terms of behavioural symptoms, as we do in this book, then there are interventions that already exist that are effective and worthwhile. This book is devoted to a presentation of five new, non-medical, worthwhile dementia interventions, and to explaining the ingredients that allow them to be classed as "worthwhile". In this chapter, we set out the fundamentals. This involves: defining what is dementia; identifying what are the types of intervention that have been tested; explaining what is necessary to establish effectiveness; and explaining the role of Cost-Benefit Analysis (CBA) in public policy decision-making related to dementia interventions.